Syrian regime bombardment on the rebel-held enclave of Eastern Ghouta killed at least 45 civilians on Monday, the Syrian Observatory for Human Rights said.
The Britain-based war monitor said at least 19 of the victims were killed in the town of Hammuriyeh, where regime aircraft used crude improvised munitions known as "barrels bombs".
The Observatory warned that toll could rise further as bodies were still being retrieved from the rubble.
Fresh air raids by the Syrian regime on the besieged rebel-held enclave of Eastern Ghouta reported earlier that 14 civilians were killed overnight, a monitor said Monday.
The Syrian Observatory for Human Rights said barrel bombs -- crude, improvised munitions that cause indiscriminate damage -- were used, including on the town of Hammuriyeh, where 10 people were killed.
The latest deaths brought to 709 the number of civilians killed since regime and allied Russian forces intensified their campaign against Eastern Ghouta in February.
According to Rami Abdel Rahman, the head of the Britain-based Observatory, at least 166 of them were children.
The deadly raids, as well as other strikes and rocket fire elsewhere in Eastern Ghouta Monday, came as the battered enclave awaited a convoy of humanitarian aid from the United Nations.
The Syrian army and its allies have captured more than a third of the rebel enclave in eastern Ghouta near Damascus since starting a ground offensive there a week ago, according to the Syrian Observatory for Human Rights.
Syrian government removes medical aid items from Ghouta convoy
Syrian government officials removed trauma kits and surgical supplies from trucks that are part of an inter-agency convoy heading into the besieged Syrian enclave of eastern Ghouta, a World Health Organization (WHO) official told Reuters on Monday.
"All trauma (kits), surgical, dialysis sessions and insulin were rejected by security," a WHO official said by email, adding that some 70 percent of the supplies loaded on its trucks leaving its warehouses had been removed during the inspection.
The United Nations said on Sunday that it had received approval for the convoy to the government-besieged area of 400,000 near Damascus, which only one small convoy reached in mid-February.
The Russian military said on Monday that Syrian militants had promised to let civilians leave their eastern Ghouta enclave near Damascus in exchange for humanitarian aid, Interfax news agency reported.
Earlier, Russia introduced a daily ceasefire in the severely bombed area but the military said that Syrian rebels had prevented local residents from leaving.